Electricity generation is the process of generating electric power from sources of primary energy, such as through electromechanical generators driven by heat engines fueled by combustion or nuclear fission, and/or through other means such as harnessing the kinetic energy of flowing water and wind. Other energy sources include solar photovoltaics and geothermal power. In most modern developed areas, electrical power is typically generated at a power plant and delivered to individual homes, businesses or other recipients through an electrical distribution grid. However, people who live on islands in oceans or lakes large enough to have reasonably constant wind, or shorelines, or similar areas may not have consistent or reliable access to an electrical grid, and it may be desirable to seek alternative methods to provide electrical power for their households. One such alternative is to install a device in a nearby body of water with wave action in order to convert the kinetic wave energy into electrical power.
The present invention seeks to provide a wave energy converter (WEC) system that meets the following criteria: 1) is not expensive, 2) can operate as well in deep as shallow water, 3) can be fully water and wind proofed so it can be sustained untended in water for long periods of time, 4) can operate well in all wind conditions, and 5) can use leverage to reduce the force necessary to generate electricity. No previous art seems to meet all these conditions. Features 2, 3 and 4 are absolutely necessary for any WEC system that is actually useable; conditions 1 and 5 are highly desirable. Unless a WEC design contains solutions to these problems, it is not likely to be of practical use.
The present invention seeks to address these problems by presenting a moveable raft with a long lever arm and a float at its opposite end. The float is stationary, connected by anchor line to the sea bed, which may be far below sea level. As the raft bobs up and down, it moves the lever at the raft end, though the float end stays stationary. This movement turns gears or pulleys which operate a generator, generating electricity. The WEC machinery on the raft is hermetically enclosed in a capsule, making it weather proof. No opening is required to allow the lever to move up and down, as is typical in prior lever-based art. The raft is designed to look like a weather vane, so it always faces into the wind. Wind or no wind, the float at the end of the lever remains stationary at trough water level, but rising waves raise the raft and WEC generating electricity. Construction of the raft and WEC can be low tech. Materials for the raft suitable for generating electric for 5 families are estimated to be relatively low-cost and suitable for application with individual households.
Prior art in which the platform and/or WEC is anchored using a post-based system (the “oil rig” anchoring system) does not allow WEC usage in deep water, except at exorbitant cost, affordable only by large communities already most likely to have electricity. The other alternative, anchor line-based prior art, simply does not work in windy conditions. These anchor line designs depend on gears or pulleys moving back and forth along the anchor line due to rising and falling waves. With wind, the gear driven WEC mechanism can be blown to the far end of the anchor line and held there by the wind as waves rise and fall; hence, there is no movement by the mechanism along the anchor line, and therefore no electricity generated. This is a flaw in its design which renders it unsuitable for practical applications. Both types of prior art seem to provide exposure to weather and salt water which could impede the WEC's functioning.
The current invention uses an anchor line to provide a cost-effective way of connecting the moving platform supporting the WEC device to the stationary sea bed, no matter how deep the water is, without the limitations found in prior art using anchor lines. The relative motion is then harvested to produce electricity. The WEC is hermetically sealed, providing full weather protection to the WEC machinery, located inside the sealed capsule. The new invention is furthermore unaffected by wind.